PUBLIC REVIEW DRAFT, OCTOBER 2008KENYA STANDARD KS 1884-1:2008 
ICS 33.120.40 
© KEBS 2008 First Edition 2008  
 
  
 
 
 
 
 
Specification — Accessories for use in 
antenna installations —   
Part 1: Splitters 
 
 
 
 
 
  
 
 
 
 
PUBLIC REVIEW DRAFT, OCTOBER 2008 
 
 
 
  
 PUBLIC REVIEW DRAFT, OCTOBER 2008KS 1884-1:2008  
ii © KEBS 2008 — All rights reserved TECHNICAL COMMITTEE  REPRESENTATION 
 
The following organizations were r epresented on the Technical Committee: 
 
Widestream Communications Limited 
Kenya Broadcasting Corporation 
Meteorological Department 
Kenya Power & Lighting Company  
Telea (K) Limited 
SR Kenya Limited 
Department of Defence 
Kenya Police Force 
Communications Commission of Kenya 
Kenya Bureau of Standards — Secretariat  
 
  
 
 
 
REVISION OF KENYA STANDARDS 
 
In order to keep abreast of progress in industry, Ke nya standards shall be regularly reviewed. Suggestions 
for improvement to published standards, addressed to  the Managing Director, Kenya Bureau of Standards, 
are welcome.  
 
  
 
 
 
  
 
© Kenya Bureau of Standards, 2008 
 
Copyright. Users are reminded that by virtue of Section 25 of the C opyright Act, Cap. 12 of 2001  of  the Laws of Kenya, copyrig ht 
subsists in all Kenya Standards and except as provided under Section 26 of this Act,  no Kenya Standard produced by Kenya Bureau  of 
Standards may be reproduced, stored in a retrieval system in any form or transmitted by any means without prior permission in w riting 
from the Managing Director. 
 
 
  
 
  
 
  
 
   
 
 
 
 
  
 PUBLIC REVIEW DRAFT, OCTOBER 2008KENYA STANDARD KS 1884-1:2008 
ICS 33.120.40 
© KEBS 2008 — All rights reserved  iii  
 
  
 
  
 
Specification — Accessories for use in antenna installations —  
 
Part 1: Splitters  
 
 
  
 
 
 
 
  
 
  
 
 
 
 
KENYA BUREAU OF ST ANDARDS (KEBS) 
 
Head  Office:  P.O. Box 54974, Nairobi-00200, Tel.: (+254  020) 605490, 69028000, 602350, Mobile: 0722202137/8, 0734600471/2; 
Fax: (+254 020)  604031 
E-Mail: info@kebs.org,  Web:http://www.kebs.org  
 
KEBS Coast Region 
P.O. Box 99376, Mombasa 80100 
Tel: (+254 041) 229563, 230939/40 Fax: (+254 041) 229448 
E-mail: kebs-msa@swiftmombasa.com KEBS Lake Region 
P.O. Box 2949, Kisumu 40100 
Tel: (+254 057) 23549,22396 Fax: (+254 057) 21814 
E-mail: kebs-ksm@swiftkisumu.com KEBS North Rift Region 
P.O. Box 2138, Nakuru 20100 
Tel: (+254 051) 210553, 210555PUBLIC REVIEW DRAFT, OCTOBER 2008KS 1884-1:2008  
iv © KEBS 2008 — All rights reserved FOREWORD 
 
This Kenya standard wa s prepared by the Communication Equipment  under the mandate of the Electrical 
Industry Standards Committee in accordance with the procedures of the Bureau and is in compliance with 
Annex 3 of the WTO/TB Agreement. 
 
 
 
 
Normative and informative annexes  
 
A 'normative' annex is an integral part of a standard, whereas an 'inf ormative' annex is only for information 
and guidance.  
  
 
  
 
  
 
Summary of development  
 
This Kenya Standard, 
having been prepared 
by the Communication 
Equipment Technical 
Committee was first 
approved by the 
National Standards 
Council in December 2008  
 Amendments issued since publication 
Amd. No. Date Text affected 
   
   
   
   
   
 PUBLIC REVIEW DRAFT, OCTOBER 2008PD/09/01/2005 
© KEBS 2006 — All rights reserved  v  
Contents 
 
1  Scope ......................................................................................................................... ........................... 1  
2  Normative re ferences .......................................................................................................... ................. 1  
3  Definitions ................................................................................................................... .......................... 1  
4  General requi rements .......................................................................................................... ................. 1  
4.1  Material ...................................................................................................................... ........................... 1  
4.2  Corrosion pr otection .......................................................................................................... ................... 2  
5  Mechanical r equirements ....................................................................................................... ............... 2  
5.1  Terminal robustness ........................................................................................................... .................. 2  
5.2  Sealing ....................................................................................................................... ........................... 2  
5.3  Continuity between input and out put — outer cabl e terminals ............................................................. 2  
6  Electrical r equirements ....................................................................................................... .................. 2  
6.1  Amplitude frequency resp onse of outputs ....................................................................................... ..... 2 
6.2  Mutual isolation between outputs .............................................................................................. ........... 2  
6.3  Return loss ................................................................................................................... ......................... 3  
6.4  Component radiation characteristic ............................................................................................ .......... 3 
7  Test methods .................................................................................................................. ...................... 3  
7.1  Corrosion prot ection te st ..................................................................................................... .................. 3  
7.2  Test for termi nal robustness .................................................................................................. ............... 3  
7.3  Sealing test .................................................................................................................. ......................... 4  
7.4  Test for amplitude frequen cy response of outputs .............................................................................. . 4 
7.5  Test for mutual isol ation between outputs ..................................................................................... ....... 4 
7.6  Test for re turn loss .......................................................................................................... ...................... 5  
7.7  Test for component radiat ion characte ristics .................................................................................. ...... 5 
7.8  Test for continuity between input and output — outer cable terminals ................................................. 9  
8  Packing and marking ........................................................................................................... ................. 9  
8.1  Packing ....................................................................................................................... .......................... 9  
8.2  Marking ....................................................................................................................... ........................ 10  
Annex A (informative)  The absorbing clamp and its app lication for the measurement of interference power 16  
Annex B (informative)  The stop filter ........................................................................................ ...................... 19  
 
 
 PUBLIC REVIEW DRAFT, OCTOBER 2008PUBLIC REVIEW DRAFT, OCTOBER 2008 
KENYA STANDARD KS 1884-1:2008  
© KEBS 2008 — All rights reserved  1   Specification — Accessories for use in antenna installations — Part 1: 
Splitters 
 
 
1 Scope 
 This part of KS 1884 specifies the mechanical and electrical requirements for splitters for use in antenna installations both indoors and outdoors, covering t he VHF/UHF television and VHP sound broadcast bands. 
 
2 Normative references 
 
The following referenced documents are indispensable for the application of this Kenya Standard. For dated 
references, only the edition cited applies. For undated references, the latest edition of the referenced document 
(including any amendments) applies.  
 
IEC 60068-2-11, Basic environmental testing procedures — Part 2-11: Tests — Test Ka: Salt mist  
 
IEC 60068-2-18, Environmental testing — Part 2-18: Tests — Test R and guidance: Water  
 
IEC 60068-2-21, Environmental testing — Part 2-21: Tests — Test U: Robustness of terminations and 
integral mounting devices  
 
IEC 60934, Circuit-breakers for equipment (CBE)  
 
3 Definitions 
 
For the purposes of this part of KS 1884, the following definitions apply: 
 
3.1 
acceptable 
acceptable to the authority administering this st andard, or to the parties concluding the purchase 
contract, as relevant 
 
3.2 mutual isolation 
isolation between outputs 
 
3.3 
return loss the difference between the forward vo ltage (or current) and the reflected voltage (or current) at the splitter 
input terminals, expressed in decibels  
3.4 
splitter 
a passive unit that splits the input signal into severa l outputs that are normally of uniform signal level 
 
3.5 
through-loss the reduction in signal level between input and output 
 
4 General requirements 
 
4.1 Material 
 
Splitters and mounting facilities shall be fabricated from a material that is suitable for use in the environment 
in which the splitter is intended to be used. PUBLIC REVIEW DRAFT, OCTOBER 2008KS 1884-1:2008  
2 © KEBS 2008 — All rights reserved  
Non-metallic materials used shall be stabilized to ultrav iolet (UV) light. 
 
4.2 Corrosion protection 
 
When a splitter and its mounting facilities, that are int ended for outdoor use, are tested in accordance with 
7.1, they shall show no sign of corrosion. (See also 6.1.) 
 
5 Mechanical requirements  
 
5.1 Terminal robustness 
 
The requirement given below applies only to splitters  where screw type terminal cable connections are 
incorporated. It does not apply where su itable terminal sockets are fitted. 
 The input and output cable connections shall be so  designed that they will accommodate a 75 Q coaxial 
cable (of dimensions specified by the splitter manufactu rer) in such a way that the characteristic impedance 
of the cable is not affected. When the splitter is test ed in accordance with 7.2, there shall be no sign of 
damage or deformation of the cable or terminals and the cable shall not have become dislodged. 
 
5.2 Sealing 
 
When a splitter that is intended for use outdoors is tested in accordance with 7.3, no water shall have 
entered the housing. 
 
5.3 Continuity between input and output — outer cable terminals 
 
When tested in accordance with 7.8, the circuit- breaker shall have tripped on each performance of the 
procedure in 7.8.2.2. When the trac k between the terminals is being inspected, there shall be no sign of 
deterioration owing to generation of heat. 
 
6 Electrical requirements 
 
6.1 Amplitude frequency response of outputs 
 
The manufacturer shall state the frequency response of the outputs and shall give the through-loss, in 
decibels, at the extreme points of the specified frequ ency range. These values are the "nominal values", and 
the "nominal line" is the straight line that joins these points.  
When determined in accordance with 7.4, the through-loss deviation, at  any frequency, from the nominal line 
shall not exceed the following: 
 
⎯ FM band - 1 dB; 
 
⎯ Band III  - 1 dB; and 
 
⎯ Band IV and V  - 2 dB. 
 
When a splitter that is intended for outdoor use is agai n tested in accordance with 7.4, after having been 
subjected to the corrosion protection test of 7.1, the resu lts of this second test shall not differ from those of 
the first. 
 
6.2 Mutual isolation between outputs 
 
When determined in accordance with 7.5, the minimu m isolation between outputs, in decibels, in the 
frequency range stated by the manufacturer shall, at a frequency of 80 MHz but reduced by 1.5 dB per 
octave, be equivalent to:  
20 + 20 log( U
n/Um)  
 
where 
 PUBLIC REVIEW DRAFT, OCTOBER 2008KS 1884-1:2008 
© KEBS 2006 — All rights reserved  3 Un is the signal level at output n; 
 
Um is the signal level at output m; and 
 
Un > Um.  
 
6.3 Return loss 
 When determined in accordance with 7.6, the return  loss within the frequency range stated by the 
manufacturer shall, at a frequency of 80 MHz but re duced by 1.5 dB per octave, be a minimum of 40 dB. 
 
6.4 Component radiation characteristic 
 When determined in accordance with 7.7, the minimum va lue for the component radiation characteristic shall 
be: 
 
⎯ 60 dB in the frequency range 5 MHz to 1000 MHz; and 
 
⎯ 37 dB in the frequency range 1 000 MHz to 1 750 MHz. 
 
7 Test methods 
 
7.1 Corrosion protection test 
 
NOTE This test is applicable only to those splitters and asso ciated mounting facilities that are intended for outdoor use or fo r use in 
situations where high humidity and temperatures are exper ienced, and is carried out after the test given in 7.4. 
 
7.1.1 Apparatus 
 
Chamber and solution, for producing the salt mist as described in IEC 60068-2-11. 
 
7.1.2 Procedure 
 7.1.2.1 Suspend the component under test, together with its mounting facilities (where supplied), as 
centrally as possible in the chamber. 
 
7.1.2.2 Subject the component to the procedure described in test Ka of IEC 60068-2-11, for a period of 24 h. 
 
7.1.2.3 Repeat 7.1.2.2 three times (i.e. to a total of four times). 
 7.1.2.4  Examine the component and its mounting facilities (w here supplied) for signs of corrosion, and then 
carry out the test given in 7.4. 
 
7.1.2.5  Check for compliance with 4.2. 
 
7.2 Test for terminal robustness 
 
7.2.1 Apparatus 
 
Clamp, suitable for mounting the component under test  (as given in 7.2.2), and capable of withstanding the 
forces given in 7.2.3. 
 
7.2.2 Mounting of the components 
 
Mount the component in the clamp and connect the coaxial cable recommended by the manufacturer to 
each outlet in turn, in accordance with the manufacturer's instructions. 
 7.2.3 Procedure 
 Follow the procedures specified in test U
a1 and test Ub of IEC 60068-2-21, once for each test, applying forces 
of 40 N and 20 N respectively to the coaxial cable. Ex amine the cable and terminals for compliance with 5.1. 
 PUBLIC REVIEW DRAFT, OCTOBER 2008KS 1884-1:2008  
4 © KEBS 2008 — All rights reserved 7.3 Sealing test 
 
7.3.1 Apparatus  
Apparatus, as specified in test Rb of IEC 60068-2-18. 
 
7.3.2 Test conditions 
 The test conditions shall be as spec ified in test Rb of IEC 60068-2-18. 
 
7.3.3 Procedure 
 
So mount the component under test in the apparatus that it will be in the direct spray of at least one shower 
head, the component being as near as possible to t he centre of the shower arrangement. Subject the 
component to a shower for 1 h and then examine it. Check for compliance with 5.2.  
7.4 Test for amplitude frequency response of outputs 
 
NOTE In the case of a splitter that is intended for outdoor use,  this test is carried out both before and after the test given in 7.1. 
 
7.4.1 Apparatus 
 7.4.1.1 Signal generator , with appropriate frequency coverage. 
 
7.4.1.2 Measuring receiver , with appropriate frequency coverage. 
 7.4.1.3 Two suitable calibrated attenuators , of appropriate impedance. These may be incorporated in the 
signal generator and receiver. 
 
7.4.1.4 Suitable coaxial changeover switch .  
 7.4.2 Procedure 
 7.4.2.1  Connect the apparatus as shown in Figure 1. 
 
7.4.2.2  With the switch in position A, so adjust attenuator  1 that the input from the signal generator to the 
component under test is at a level comparable to that encountered in use.  7.4.2.3  With the switch in position A, adjust attenuator  2 to obtain the convenient  reading on the measuring 
receiver, and record the attenuation in attenuator 2 as U
a dB. 
 
7.4.2.4  With the switch in position B, reduce the att enuation in attenuator 2 to restore the level obtained in 
7.4.2.3, and record the attenuation in attenuator 2 as Ub dB. 
 7.4.2.5  Record the through-loss U
a - Ub. 
 
7.4.2.6  Measure and record the through-loss at the end frequencies of the frequency range claimed by the 
manufacturer and at a sufficient number of frequencies wi thin this range to enable a curve of through-loss 
against frequency to be plotted.  7.4.2.7 Check for compliance with 6.1. 
 
7.5 Test for mutual isolation between outputs  
 
7.5.1 Apparatus  
7.5.1.1  Signal generator , with appropriate frequency coverage. 
 7.5.1.2  Measuring receiver , with appropriate frequency coverage. 
 
7.5.1.3  Three suitable calibrated attenuators , of appropriate impedance. Two of these may be 
incorporated in the signal generator and receiver. 
 PUBLIC REVIEW DRAFT, OCTOBER 2008KS 1884-1:2008 
© KEBS 2006 — All rights reserved  5 7.5.1.4 Suitable coaxial changeover switch . 
 
7.5.2 Procedure 
 
7.5.2.1  Connect the apparatus as shown in Figure 2. 
 7.5.2.2  Set the signal generator to an unmodulated frequency within the desired range, and, with the switch 
in position B, adjust attenuator 1 to give a co mparable input level to that encountered in use. 
 
7.5.2.3  Adjust attenuator 2 to give a suit able reading on the measuring receiver. 
 
7.5.2.4  With the switch in position A, use attenuator 3 to insert attenuation until the reading on the 
measuring receiver is the same as that obtained in 7. 5.2.3. The amount of attenuation inserted is the mutual 
isolation between outputs at the frequency of measurement. 
 7.5.2.5  Record the signal levels U
n and Um at the outputs n and m respectively. 
 
7.5.2.6  Measure and record the mutual isolation at th e end frequencies of the manufacturer's stated 
frequency range and at a sufficient number of frequencies  within this range to enable a curve of mutual 
isolation against frequency to be plotted.  7.5.2.7  Check for compliance with 6.2. 
 
7.6 Test for return loss  
 
7.6.1 Apparatus 
 
7.6.1.1 Signal generator , with appropriate frequency coverage. 
 7.6.1.2 Measuring receiver , with appropriate frequency coverage. 
 
7.6.1.3 Terminating impedance , for every output port of the item under test. 
 
7.6.1.4 Standing wave ratio (SWR) measuring bridge .  
 
7.6.2 Procedure 
 7.6.2.1 Connect the apparatus as shown in Figure 3. 
 
7.6.2.2  Using an unmodulated signal that is within the ma nufacturer's stated frequen cy range and at a level 
comparable to normal use, calibrate the SWR measur ing bridge in accordance with the manufacturer's 
manual, and record the reference level A
1. 
 
7.6.2.3  Connect the component under test to the test port of the bridge and, without altering the level of the 
signal generator, note the reading A 2 on the measuring receiver. The return loss is given by (A 1 – A 2)dB. 
 7.6.2.4  Measure and record the return loss at the end fr equencies of the frequency range stated by the 
manufacturer and at a sufficient number of frequencies wi thin this range to enable a curve of return loss 
against frequency to be plotted.  7.6.2.5  Check for compliance with 6.3. 
 
7.7 Test for component radiation characteristics 
 
In the frequency range 30 MHz to 300 MHz, most of the radiation is from input and output cables and 
therefore the absorbing clamp method is  specified; but in the frequency ra nge 300 MHz to 1 GHz, the splitter 
itself could radiate and therefor e a "substitute radiation method" of measurement, with and without a 
connected output cable, is specified. 
 
7.7.1 Apparatus 
 
7.7.1.1 Signal generator , that covers the appropriate frequency range and is of sufficient output power. 
 PUBLIC REVIEW DRAFT, OCTOBER 2008KS 1884-1:2008  
6 © KEBS 2008 — All rights reserved 7.7.1.2 Absorbing clamp , that conforms to the description in A nnex A (for absorbing clamp method only). 
 
7.7.1.3 Stop filter , as described in Annex B (for radiation method only). 
 
7.7.1.4 Transmitting dipole antenna , of known radiation characteristics and suitable for the required 
frequency range (for radiation method only).  
7.7.1.5 Receiving antenna , of known radiation characteristics and suitable for the required frequency range 
(for radiation method only).  7.7.1.6 Measuring set , of appropriate impedance and that co vers the required frequency range. 
 7.7.1.7 Measurement cable , at least 0.5 A in length (at the lowest frequency of interest) plus 2 m, and of 
appropriate impedance.  7.7.1.8 Shielded terminating loads , of appropriate impedance and design. 
 7.7.1.9 All necessary coupling devices , of appropriate design. 
 
7.7.1.10 Absorbing devices, such as ferrite rings , sufficient to suppress signals from the equipment under 
test on its input. 
 
7.7.1.11 Suitable calibrated attenuator , of appropriate impedance. 
 
7.7.1.12 Suitable coaxial changeover switch . 
 
7.7.2 General measurement requirements 
 The test cables, coupling devices and terminations  shall all be well matched and well screened. Test 
equipment should normally be 75 Ω impedance. 
 
An indoor or an outdoor test site may be used. When an indoor test site is selected, the room shall be of 
sufficient size. Any reflecting and absorbing objects sh all be so positioned or sufficiently moved from the 
measurement set-up that they do not influence the results. 
 7.7.3 Equipment layout and connections 
 
The measurement set-up and equipment layout for the absorbing clamp method (frequency range 30 MHz to 
300 MHz), which is outlined in 7.7.5, is shown in Figures 4, 5 and 6. 
 The measurement set-up and equipment layout for the radiation method (freq uency range 300 MHz to 1 
GHz), which is outlined in 7.7.6, is shown in figures 7, 8 and 9.  
The component under test shall be placed at a heigh t of approximately 1 m above the ground, on a non-
metallic support on which the absorbing clamp or stop filter can be accommodated and moved. 
 
The output of the component under test shall be connected to a measurement cable of the same 
characteristic impedance and the cable shall be termi nated with the nominal impedance of the output via the 
attenuator and coaxial switch.  
Well screened cables shall be connected to the terminal s of the component under test as specified by the 
manufacturer. When a direct connection cannot be made owing to the dimension of the well screened cable, 
a connector shall be used (see Annex A).  The unused outputs, if any, of the component under test shall be te rminated with their nominal impedance by 
means of non-radiating loads connected dire ct, without any cabling (see Figure 10). 
 
The signal generator coaxial cable shall be provided with  suitable absorbing devices (e.g. ferrite rings), 
placed close to the component under te st, to avoid measurement errors. 
 
7.7.4 Operating conditions 
 PUBLIC REVIEW DRAFT, OCTOBER 2008KS 1884-1:2008 
© KEBS 2006 — All rights reserved  7 The component under test shall be operated in accordance with the manufacturer's recommendations and 
shall be tested with a signal input to the splitter t hat is equal to the maximum input specified by the 
manufacturer.  Measurements shall be performed on all output ports in  turn, and at the highest and lowest frequencies in 
the range specified by the manufacture r, and at a selection of intermediat e frequencies so chosen as to give 
a realistic representation of the radiation patte rn throughout the operating frequency range. 
 7.7.5 Procedure (absorbing clamp method — frequency range 30 MHz to 300 MHz) 
 
For sensibly consistent results t he disposition of the signal generator cable preceding the absorbing clamp, 
the signal generator mains lead and the meas urement cable beyond the absorbing clamp, and their 
proximity to other items, shall not influence the readings on the measuring set by more than ±1 dB. This shall 
be checked by moving the cables and by running a hand along their length after the equipment has been set up in accordance with Figures 4, 5 and 6.  
7.7.5.1  With the equipment set up as shown in Figures 5 and 6 and the measurement cable coupled to an 
output port of the component under test, position the absorbing clamp at the component end of the 
measurement cable and place the coaxial switch in the "check level" mode. Adjust the signal generator to the 
test frequency and to an input level that equates to t he maximum rated output level of the component under 
test. Record this input level V
i (in microvolts) from the signal generator. 
 
7.7.5.2 Tune the measuring set. Turn the coaxial switch to  the "measure radiation" mode. Set the calibrated 
attenuator to 0 dB. Move the absorbing clamp along the cable away from the component until a maximum 
reading is obtained on the measuring set (at a spacing of ±0.5 λ). Record the level of the reading Vm 
obtained. 
 
7.7.5.3 Repeat the procedure in 7.7.5.1 and 7.7.5.2 for each  output port and at the frequencies specified in 
7.7.4. 
 
7.7.5.4  From the preceding tests, the highest reading of Vm obtained for each frequency then has to be 
converted to the "substituted radiation power" pm, using the calibration chart of the absorbing clamp. Convert 
into power form p, the values of Vi recorded. Calculate the component radiation characteristic, in decibels, 
from the following formula: 
 
Cfx =10log pi/pm  
 where 
 
Cfx   is the component radiation characteristic at frequency x; 
 
p
i      is the maximum input power (as used for the measurement); 
 
pm    is the maximum value of substituted radiated power obtained at frequency fx; and 
 
fx     is one of the frequencies of measurement.  
 
7.7.5.5 Check for compliance with 6.4.  
 
7.7.6 Procedure (radiation method — 300 MHz to 1 GHz) 
 
For sensibly consistent results, the combined residual  radiation and pick-up of the test set shall at all 
frequencies be at least 20 dB lower than the expected measurement value.  This shall be checked after the first component radiat ion measurement and before the result is recorded, by 
removing the component under test and, with the i nput and output leads correctly terminated and the 
position of these connecting leads and other test e quipment otherwise unchanged, measuring the residual 
radiation. The residual radiation measured shall be at least 20 dB lower than that measured, or expected to 
be measured, with the component connected. If this ca nnot be achieved, repositioning of the test equipment 
may be helpful.  
The positioning of the transmitting and receiving an tenna shall be carefully adjusted to ensure sensibly 
consistent results over the required frequency range. PUBLIC REVIEW DRAFT, OCTOBER 2008KS 1884-1:2008  
8 © KEBS 2008 — All rights reserved  
This shall be checked with a transmitting antenna conn ected horizontally in place of, and in the same 
position as, the component under test, and parallel with the receiving antenna not less than 1.3 m away. A test shall then be carried out to ensure that, when the transmitting antenna is moved vertically, or laterally, by 
± 10 cm, the measuring set readings do not vary by more  than ± 1.5 dB. This test  shall be repeated at each 
test frequency and the distance d and the height h adjusted until this requirement is met (see figure 9). 
 
The antennae positions, supports, etc., shall then be moved round in the horizontal plane by 90°, keeping 
the same precise spacing distance between the antennae. The new reading obtained shall be noted. 
If the readings vary by more than 3 dB, the following may be required:  
a) change the size of the room; 
 
b) add metallic layers or plates to improve reflection properties of the ground; 
 c) use a corner reflector antenna; and 
 
d) add absorbing material to the walls.  7.7.6.1 Measurement procedure without measurement cable (all output ports terminated) 
 
7.7.6.1.1 With the equipment connected as in Figures 7 and 9 and the coaxial switch in the "measure 
radiation" mode, adjust the signal generator to the te st frequency and to an input level that will give the 
maximum rated output level from the component under test. Record this input level V
i from the signal 
generator. Tune the measuring set and adjust the controls  to give a convenient reading. Then rotate the 
component under test in all planes, until the maximum reading Vr is obtained, and record this reading. 
 
7.7.6.1.2 Substitute the transmitting antenna for the component u nder test, and so place it that it is parallel 
with the receiving antenna and that its centre corres ponds to that of the component under test (when the 
component is in position). Adjust the output level of the signal generator to give the same reading Vr on the 
measuring set. The available power from the generator to  the transmitting antenna is the substituted radiated 
power ps from the component under test. Record this value. 
 
7.7.6.1.3 Repeat this procedure for each of the test frequencies specified in 7.7.4. 
 
7.7.6.1.4 The highest reading of ps obtained at each frequency in the preceding test indicates the radiation 
characteristic of the component, expres sed as the substituted radiated power. 
 7.7.6.1.5  Calculate the component radiation characterist ic, in decibels, from the following formula: 
 
Cfx  = 10log p
i/ps  
 
where 
 
Cfx   is the component radiation characteristic at frequency x; 
 p
i      is the maximum input power (as used for the measurement); 
 
ps      is the maximum value of substituted radiated power obtained at frequency fx; and 
 
fx     is one of the frequencies of measurement. 
 
7.7.6.1.6 Check for compliance with 6.4. 
 
7.7.6.2 Measurement procedure with measurement cable connected to one port 
 7.7.6.2.1 With the equipment connected as in Figures 8, 9 and 10 and the coaxial switch in the "measure 
radiation" mode, connect the measurement cable to the port to be tested. So position the measurement 
cable, with stop filter in position at the component end,  that it is parallel to the receiving antenna. Adjust the 
signal generator to the test frequency and to an input le vel that will give the maximum rated output level from 
the component under test. 
 PUBLIC REVIEW DRAFT, OCTOBER 2008KS 1884-1:2008 
© KEBS 2006 — All rights reserved  9 Record this input level V\ from the signal generator. Tune the measuring set and adjust the controls to give a 
convenient reading. Tune the stop filter  to the calibration mark for the test frequency in use (as determined in 
Annex B). Move the stop filter along the cable, away from the component, until a maximum reading is 
obtained on the measuring set (at a spacing of ± 0.5 λ). By observing the meter reading whilst making fine 
adjustments to the filter tuni ng, check that the stop filter is correctl y tuned. Then rotate the component under 
test in all planes, to determine whether a higher reading  can be obtained. If it can, readjust the position of the 
stop filter, etc., and record the final maximum reading Vm. 
 
7.7.6.2.2 Substitute the transmitting antenna for the component u nder test, and so place it that it is parallel 
with the receiving antenna and that its centre corres ponds to that of the component under test (when the 
component is in position). Adjust the output leve l of the signal generator to give the same reading Vm on the 
measuring set. The available power from the signal gene rator to the transmitting antenna is the substituted 
radiation power ps from the component under test. Record this value. 
 7.7.6.2.3 Repeat this procedure for each of the test frequencies specified in 7.7.4. 
 
7.7.6.2.4  Repeat this procedure for each of the measurement ports specified in 7.7.4. 
 
7.7.6.2.5  The highest reading of p
s obtained at each frequency in the pr eceding test and in the test given in 
7.7.6.1, indicates the radiation char acteristic of the component, expresse d as the substituted radiated power. 
Using the above ps value and the V1 values recorded, but converted into power form pit calculate the 
resultant component radiation characteristic at each frequency, in decibels, from the following formula: 
 
Cfx    = 10log pi/ps  
 
where 
 
Cfx   is the component radiation characteristic at frequency x; 
 
pi      is the maximum input power (as used for the measurement); 
 
ps     is the maximum value of substituted radiated power obtained at frequency fx; and 
 
fx     is one of the frequencies of measurement. 
 
7.7.6.2.6  Check for compliance with 6.4. 
 
7.8 Test for continuity between input and output — outer cable terminals  
 
7.8.1 Apparatus 
 7.8.1.1 20 A moulded-case circuit-breaker , that complies with the relevant clauses of IEC 60934. 
 
7.8.1.2 Load resistor , with a resistance of approximately 7 Ω and that is capable of carrying 20 A for a 
period equal to the time taken for the circuit-breaker to trip.  
7.8.1.3 Mains switch , capable of carrying a minimum of 30 A.  
 
7.8.2 Procedure 
 7.8.2.1 Connect the apparatus as shown in Figure 11. 
 
7.8.2.2 Switch the apparatus on and ensure that the circ uit-breaker has tripped, then switch the apparatus 
off and restore the circuit-brea ker to its operational state. 
 
7.8.2.3  Repeat the procedure specified in 7.8.2.2 a further nine times (i.e. to a total of 10 times). 
 
7.8.2.4  Check for compliance with 5.3. 
 
8 Packing and marking 
 
8.1 Packing PUBLIC REVIEW DRAFT, OCTOBER 2008KS 1884-1:2008  
10 © KEBS 2008 — All rights reserved  
Each splitter shall be so acceptably packed as to protect it from damage during normal handling, 
transportation and storage. 
 
8.2 Marking 
 
The splitter shall bear the following information:  
a) the manufacturer's trade name or trade mark or both; 
 
b) the frequency range for which the splitter has been designed; 
 
c) identification marks for the input and output(s); and 
 
d) whether or not the splitter is suitable for outdoor use. 
 
NOTE It is advisable, in addition, to pr int the above information on the packaging. 
 
 
 
 
 
 
Figure 1 — Apparatus for test for amplitude frequency response of outputs 
  
 
 
 
 
Figure 2 — Apparatus for test for mutual isolation between outputs 
 
 
 
 PUBLIC REVIEW DRAFT, OCTOBER 2008KS 1884-1:2008 
© KEBS 2006 — All rights reserved  11  
 
 
 
 
 
Figure 3 — Apparatus for test for return loss 
  
 
 
 
 
 
 
Key 
1 Component under test 
2 Absorbing clamp 
3 Measuring set 4 Signal generator 
5 Terminating resistor 
6 Measurement cable 
 
Figure 4 — Measurement set-up — Test for screening attenuation absorbing clamp method 
(frequency range 30 MHz to 300 MHz) 
 
 
 PUBLIC REVIEW DRAFT, OCTOBER 2008KS 1884-1:2008  
12 © KEBS 2008 — All rights reserved 
 
Key 
1 Component under test 
2 Absorbing clamp 
3 Measuring set 4 Signal generator 
5 Terminating resistor 
6 Measurement cable 
 
  
Figure 5 — Absorbing clamp method (frequency range 30 MHz to 300 MHz) 
 
 
 
 
 
Key 
1 Component under test 2 Absorbing clamp 
3 Measuring set 
4 Signal generator 5 Absorbing device 
6 Terminating resistor 
7 Measurement cable 8 Coaxial switch 9 Attenuator 
 
 
 
Figure 6 — Example of general measurement set-up for frequency range 30 MHz to 300 MHz 
 PUBLIC REVIEW DRAFT, OCTOBER 2008KS 1884-1:2008 
© KEBS 2006 — All rights reserved  13 
 
Key 
1 Component under test 
2 Receiving antenna 
3 Measuring set 4 Signal generator 
5 Terminating resistor 
 
 
 
Figure 7 — Radiation method (frequency range 300 MHz to 1 GHz) without measurement cable 
 
 
 
 
Key 
1 Component under test 
2 Receiving antenna 
3 Measuring set 4 Signal generator 
5 Terminating resistor 
6 Measurement cable 
7 Stop filter 
 
 
 Figure 8 — Radiation method (frequency range 300 MHz to 1 GHz) with measurement cable 
 
 PUBLIC REVIEW DRAFT, OCTOBER 2008KS 1884-1:2008  
14 © KEBS 2008 — All rights reserved 
 
Key 
1 Component under test 
2 Stop filter 
3 Measuring set 4 Signal generator 
5 Absorbing device 
6 Coaxial switch 
7 Attenuator 
8 Measurement cable 
9 Receiving antenna 10 Terminating resistor 
 
 
 
Figure 9 — Example of measurement set-up for frequency range 300 MHz to 1 GHz 
 
 
Key 
1 Component under test 2 Absorbing device 
3 Non-radiating resistor 
4 Unused output 5 Measurement cable 
6 From the generator 
 
 
Figure 10 — Termination of component with several outputs 
 
  
 PUBLIC REVIEW DRAFT, OCTOBER 2008KS 1884-1:2008 
© KEBS 2006 — All rights reserved  15 
 
where 
A is the unit under test; 
CB is the 20 A circuit breaker; 
R is the load resistor; and  
S is the main switch. 
 
 
Figure 11 — Circuit arrangement for test for conti nuity between input and output terminals of the 
outer cable PUBLIC REVIEW DRAFT, OCTOBER 2008KS 1884-1:2008  
16 © KEBS 2008 — All rights reserved  
Annex A 
(informative) 
 
The absorbing clamp and its application fo r the measurement of  interference power 
 
A.1 General 
 
The general method is shown in Figure A.1. The test l ead B is connected direct from the appropriate port of 
the component under test, A. C is a current transform er or current probe placed around the test lead that 
provides an output voltage proportional to the resultant cu rrent in the lead. D and E are ferrite tubes or series 
of ferrite rings that surround respec tively the test lead and the screened lead to the measuring instrument. As 
shown in Figure A.2, a satisfactory device that co vers the frequency range 30 MHz to 300 MHz has been 
constructed, using 56 rings of ferrite for D and 60 simila r rings for E. The current transformer C is made of 
three such rings encircled by a single turn of screen ed wire. C and D are mounted in fixed relative positions 
as close together as practicable, in such a way that the distance d can be varied. Both D and E serve to load 
their respective cables and to attenuate currents flowing along them. 
 
A.2 Mains lead testing 
 When the lead under test forms the main supply and the h.f. isolat ion between the mains supply and the 
input of the measuring device on t he side of the appliance appears to be insufficient, a fixed ferrite absorber 
F should be placed along the mains lead at a distanc e of approximately 4 m from the appliance. This 
improves the stability of the loading impedance a nd reduces extraneous noise coming from the mains 
supply. 
 A.3 Position of measuring device 
 
When the connector of the measured appliance makes it impossible to pos ition the measuring device at the 
first maximum, the second maximum may be used, the lead being extended via connector G. The reading should be increased by 1 dB (see curve B in Figure A.4). 
 
A.4 Test lead length 
 
The straight portion of the test lead should be about ( λ
maxI2) + 60 in order to allow the positioning of the 
measuring devices at any time ( λmax is the wavelength corresponding to the lowest frequency at which 
measurements are to be made). 
 
A.5 Calibration of measuring device 
 
When the measuring device is being calibrated, it is assemb led as in Figure A.1, except that the test lead is 
replaced by an insulated wire of e ffective cross-sectio n approximately 1 mm2 to 2 mm2 and that the end that 
is normally connected to the appliance,  is connected instead to the centre pin of a connector arranged to 
feed through the wall of a screened enclosure. A generator with 75 Ω output impedance is connected to the 
other end of the connector through a 75 Ω attenuator that has an attenuati on of at least 10 dB (see Figure 
A.3).  
The measuring device is then positioned for maximum indication. From the generator output indication and 
attenuator setting, a calibration curve can be drawn in terms of the available power at the output of the 
attenuator.  
A.6 Method used to establish the calibration curve shown in Figure A.4 
 
The calibration described in A.5 can be assumed to be a measurement of the inse rtion loss of a quadripole. 
The input of the two-port is effectivel y at the coaxial terminal in the wa ll of the screened room and the output 
is at the input of the measuring receiver.  
As a precaution, and to avoid possible spurious effect s of mismatch in the cable, a 10 dB attenuator is 
inserted before the coaxial connector. Wh en the switch S is in the position shown in Figure A.3, a signal is 
injected and the receiver indication is noted. When the absorbing device is adjusted for maximum response, 
the attenuation position A
1 of the generator is noted. The generator is  then connected to the receiver direct, 
and the attenuator is adjusted to A 2 to give the same reference reading. PUBLIC REVIEW DRAFT, OCTOBER 2008KS 1884-1:2008 
© KEBS 2006 — All rights reserved  17  
The insertion loss shown in Figure A.4, is given by:  
 
(A1 - A 2 - 10) dB (curve A, first maximum). 
 
It can be shown that, if the generator and the receiver each has an internal resistance of 75 Ω, and if the 
insertion loss of the measuring device (after the 10 dB  attenuator) is 18.75 dB, the indication on the receiver 
expressed in decibels (microvolts) has the same numerical value as the available power expressed in 
decibels (picowatts) at the output of the signal generator. This is the reason for the correction scale shown in 
Figure A.4. The correction scale gives the factor, in dec ibels, to be added to the indication of the receiver in 
decibels (microvolts), to convert the reading to power in decibels (picowatts). 
 
 
Key 
A Component under test 
B Test lead 
C Current transformer/probe D Ferrite tubes/rings 
E Ferrite tubes/rings 
F Ferrite absorber 
G Connector H CISPR receiver 
 
 
Figure A.1 — Schematic diagram — Measurement of interference power between 30 MHz and 300 
MHz 
 
  
 
Key 
A Signal generator B Test lead 
C Current transformer/probe 
D Ferrite tubes/rings E Ferrite tubes/rings 
 
Figure A.2 — Detail of absorbing clamp 
 PUBLIC REVIEW DRAFT, OCTOBER 2008KS 1884-1:2008  
18 © KEBS 2008 — All rights reserved 
 
Key 
A Signal generator 
B Test lead 
C Current transformer/probe 
D Ferrite tubes/rings 
E Ferrite tubes/rings F Ferrite absorber 
G CISPR receiver 
S Coaxial switch 
 
 
Figure A.3 — Schematic diagram — Calibration of the absorbing clamp between 30 MHz and 300 MHz 
 
 
 
 
 
Figure A.4 — Calibration of the absorbing clamp (example) PUBLIC REVIEW DRAFT, OCTOBER 2008KS 1884-1:2008 
© KEBS 2006 — All rights reserved  19  
Annex B 
(informative) 
 
The stop filter 
 
B.1 Function 
 
The stop filter has to give an effect ive blocking of either the radio-freque ncy current flowing on the outside of 
a screened cable or the asymmetrical  radio frequency currents flowing in a mains lead. It is tuned to a 
specific frequency, which should be  variable over a certain range. 
 
The layout of a stop filter is shown in Figure B.1. The stop filter works as  a quarter wave stub. It is made from 
two concentric metal tubes at some distance from each other. The coaxial cable or the mains lead passes 
through the inner tube, without making any metallic co ntact with the filter. A short-circuiting plunger is 
inserted between the two tubes. This short-circuit is tr ansformed to a very high impedance at the open end of 
the filter a quarter wave-length away. Therefore a current in the filter of a frequency that corresponds to the 
quarter wave-length will be zero at the open end. As the diam eter of the stop filter is much less than a wave-
length, the currents at the same frequency that fl ow on the outside of the screened cable, or the 
asymmetrical currents in the conductors of the mains le ad, have to be zero at the point where the cable, or 
mains lead, enters the stop filter.  
B.2 Construction 
 
The inner one of the two metal tubes of the stop filter could be mounted in side the outer one by means of a 
metallic support at the far end of the filter. This supp ort should be so strong that  no other support than the 
short-circuiting plunger is needed for a stop filter used  at UHF. For lower frequencies, the corresponding long 
length of the filter will necessitate a support at t he end towards the component under test. This support 
should be made of insulating material that has a low power factor. 
 
Means should be provided to adjust the position of the plunger, for instance by one or more rods connected 
to the plunger and penetrating through the short-circuit support at the far end of the filter or by handles 
connected to the plunger and penetrating through lo ngitudinal slots in the outer tube of the filter. 
 
B.3 Frequency calibration 
 
Owing to the "edge effect" at the input end of the two t ubes, the frequency calibration of the stop filter is not 
given direct by the geometrical dist ance from the input end to the short-circuit. Instead, the calibration is 
made by inserting a single insulated conductor through the filter; at the input end of t he filter, the conductor is 
connected to a signal generator and at the far end, it is connected to a receiver. No connections should be 
made between the earth of the signal generator, or receiv er, and the stop filter. For each frequency of tuning 
of the signal generator, the stop filter should be t uned by so moving the short-circuiting plunger that a 
minimum indication is observed at the receiver. A calibration curve can then be made. Because a single 
conductor is used and the earth is not defined, parasitic resonances can occur in the calibrating set-up, 
which can give rise to calibration errors. For this reason, the calibration should be carried out carefully, by checking that the calibration curve is smooth. 
 
  
 
 
 
  PUBLIC REVIEW DRAFT, OCTOBER 2008KS 1884-1:2008  
20 © KEBS 2008 — All rights reserved 
 
Key 
A To the component 
B Coaxial cable or mains lead 
C Movable short- circuiting plunger 
 
Figure B.1 — Stop filter